This blog discusses current weather, weather prediction, climate issues, and other topics

Thursday, November 5, 2015

Snow in Our Future

The Northwest Snow and Avalanche Workshop is on this weekend (see below) and the number one question I am getting from folks is about the upcoming ski season. So lets talk snow.

In the short term, there is good news. First, the storm last weekend left several inches to a foot at higher elevations. Here is the MODIS satellite image from yesterday, followed by one from Sept 30th. Big difference. (Note there are some clouds in each of them). Snow in terrain has a dendritic pattern. On Sept 30, there was basically no snow, just glacial ice. Not so yesterday, with extensive snow found at elevations about 4000 ft.

Yesterday

Sept 30th

Stevens and Crystal both have around a foot at some of their higher runs (see pics)

10 inches measured at Crystal

Stevens

And there is going to be plenty of snow during the next week, particularly the end of the week. The pattern that is setting up (see upper level map below) shows the jet stream slipping south of us and our region in cool northwesterly flow with an embedded trough. Snow lovers know this is a good pattern.

The UW WRF model snow accumulation forecast for the 72 h ending Wednesday at 4 PM shows massive snow in the north Cascades and in SW British Columbia: several feet, with the Olympics and southern Cascades receiving substantial amounts. Even the Sierra Nevada gets snow. We haven't seen model predictions like that for a LONG time.

We are seeing very different large scale weather patterns than last year and there is no reason, with the game-changing El Nino going on, to expect a complete snow bust like last year. The meteorological cards have been shuffled in a big way.

I suspect there will be enough snow for an early, limited opening at some of the higher elevation regional ski areas by the end of next week. Yes, some rocks and limited runs, but a start. El Nino warming tends to be most acute after the start of the new year and that tends to reduce the end of winter ski season. But the beginning of El Nino years can often provide good skiing opportunities.

Now I am NOT going to tell you whether you should purchase that annual ski pass. Be your own judge of that. Certainly, our ski industry needs your business. But if you want to learn more about snow and avalanches, you might go to the snow workshop on Sunday. Avalanche safety and knowing the ways of mountain weather are always valuable when you head into the mountains during winter.

___________________________________The Northwest Snow and Avalanche Workshop is this weekend (November 8th). Lots of great talks and a big crowd of snow lovers. For more information on the meeting and how you can attend, go here.

There is every expectation that El Nino will give us less snow this winter than usual. Maybe 15% lower than average for many locations. But that's still a LOT more than last year, which was like 75% lower.

So yes, we still should worry about the El Nino and act accordingly when it comes to managing water resources. But likely this winter will look really good compared to last year.

Will the water resources catch up with normal? Not likely. We're starting in a hole and we'll likely have less snow than usual, especially after the new year.

Yes, but we're likely NOT in some "permanent" El Nino set up that will extend into the 2016 - 2017 Winter either. Professor Mass has pointed this out. Obviously, the actual conditions have to play out too (not just the models).

While we're not catching up in the short-term, assuming the climate cycles back to wetter conditions ... gradually we will catch up to normal.

@Joseph RatliffAgree that long-term averages change slowly, and anomalies like the last couple of years (and likely this winter) will shift the other way over time.

But that said, my point is to not let up on managing the drought until we're clearly on the other side of the mean. It's possible that we will all have to get better at reacting quickly and managing larger than normal excursions from the norm. Better to be prepared to do that than to get too complacent.

Historically, some of these anomalies can become entrenched for long periods. We had the Little Ice Age from around 1300AD to well into the 19th century, which was pretty miserable following the Medieval Warm Period. By the end of the 18th century, when Vancouver was exploring this region, the glaciers were HUGE. Glacier Bay, Alaska had ice protruding out into well-named Icy Strait. Today you have to cruise 40+ miles inland to find the edge of the first glacier.

It's quite possible that the warming trend we are in still has a lot of gas left, particularly as we feed it with excess CO2. A few weeks of seasonal rain won't fix that. The real issue is whether we are in for a horrifically dry winter again like last year. So far, so good.

Historically, La Nina follows El Nino. This is already showing up in the long term models. The models are showing this change to take place this summer. La Nina winters here in Seattle are usually interesting...if you like snow and cold.